Numerous of polyolefin catalysts have been developed which provide polyolefins with certain properties. One class of these catalysts are metallocenes, organometallic coordination complexes containing two .pi.-bonded moieties in association with a metal atom from Groups IIIB to VIII or the Lanthanide series of the Periodic Table of Elements. These catalysts are reportedly highly useful in the preparation of polyolefins because they produce homogeneous polymers at excellent polymerization rates, allowing one to closely tailor the final properties of the polymer as desired.
A new class of olefin polymerization catalysts have now been discovered which, when combined with a cocatalyst, such as aluminoxane, form a catalyst composition having very good polymerization activity and productivity, are easily prepared, inexpensive, and have excellent processing characteristics. The catalysts are complexes of transition metals, substituted or unsubstituted .pi.-bonded ligands and heteroallyl moieties.
Complexes of transition metals and cyclopentadienyl-type ligands with various other functionalities are well known. For example, U.S. Pat. No. 5,279,999 relates to catalyst compositions obtained by contacting a Group IVB metal compound of the formula (Cp).sub.p MeX.sub.4-p, wherein each Cp is a substituted cyclopentadienyl group; Me is a Group IVB metal; each X is a hydrocarbyl group, alkoxy or aryloxy group, alkylamide or arylamide group, hydrogen, or halogen; and p is from 1 to 4.
U.S. Pat. No. 5,194,532 describes another catalyst represented by the formula LTi(NR.sub.2).sub.3, wherein L is a .pi.-bonded ligand selected from indenyl, C.sub.1 -C.sub.4 alkyl substituted indenyl, and --OSiR.sub.3 substituted indenyl; and R is a C.sub.1 -C.sub.4 alkyl group.
U.S. Pat. No. 5,227,440 relates to supported catalysts containing a Group IVB transition metal component of the formula: ##STR2## wherein M is Zr, Hf, or Ti in its highest formal oxidation state; (C.sub.5.eta.5-y-x R.sub.x) is a cyclopentadienyl ring (or fused aromatic ring system) containing up to five substituents R; (JR'.sub.z-1-y) is a heteroatom ligand in which J is a Group VA element with a coordination number of three or a Group VIA element with a coordination number of two; and each R' is a C.sub.1 -C.sub.20 hydrocarbyl, substituted hydrocarbyl radical, or any other radical containing a Lewis acidic or basic functionality; each Q is any univalent anionic ligand; T is a covalent bridging group containing a Group IVA or VA element; and L is a neutral Lewis base.
EP 0 595 390 A1 discusses a catalyst system containing a bis(cyclopentadienyl) bis(amide) derivative of a Group IVB element.
Hughes et al., Organometallics, Vol. 12, No. 5, p. 1936 (1993) discloses various cyclopentadienyl-amide-Group IV metal complexes and their synthesis.
U.S. Pat. No. 3,542,693 relates to a catalyst system for the copolymerization of ethylene with other unsaturated hydrocarbons consisting of the product obtained by mixing, in an inert solvent, a vanadium salt, an alkyl aluminum dihalide, and a N,N-disubstituted carbamate having the formula: ##STR3## wherein R and R' are hydrocarbon radicals that contain no unsaturation other than that derived from aromatic radicals.
EP 0 520 811 A2 and U.S. Pat. No. 5,331,071 relate to catalyst systems containing metal-alkoxide complexes. EP 0 520 811 A2 discloses a catalyst component comprised of a first compound of the formula M.sup.1 (OR.sup.1).sub.p R.sup.2.sub.q X.sup.1.sub.4-p-q, wherein M.sup.1 is Ti, Zr, or Hf; R.sup.1 and R.sup.2 are each hydrocarbon moieties of 1-24 carbons; and X.sup.1 is a halogen; and a second compound that is an organocyclic compound having two or more conjugated double bonds. U.S. Pat. No. 5,331,071 relates to a catalyst component derived from reacting a compound of the formula Me.sup.1 R.sup.1.sub.n X.sup.1.sub.4-n, a compound of the formula Me.sup.2 R.sup.2.sub.m X.sup.2.sub.z-m, an organocyclic compound having two or more conjugated double bonds and a carrier material. Me.sup.1 is Zr, Ti, or Hf; R.sup.1 is a C.sub.1 -C.sub.24 hydrocarbon; and X.sup.1 is a halogen. Me.sup.2 is a Group I-III element; R.sup.2 is a C.sub.1 -C.sub.24 hydrocarbon; and X.sup.2 is a C.sub.1 -C.sub.12 alkoxy group or a halogen atom.
However, none of the above teach or suggest coordination complexes of Group IVB transition metals, substituted or unsubstituted, .pi.-bonded ligands and heteroallyl moieties or the use of such complexes as catalysts for the polymerization of olefins.